Hey, Filips, I also faced this problem. The client bought one of my projects and wrote that the project does not working, and AE to issue this error … But, no one has bought the project (other than this client) was not such a problem. The funny thing is that the guys from Adobe say that this error occurs when everything seems to be working, but for some reason does not work. I think you should try to open the project on another computer. If anyone knows the solution – help would be very useful

well my case was really strange. File was marked as CS3 . When I opened it with CS4 it gave the usual CS3 file in AE CS4 message. then it gave few errors. Some were about having parts of CS5 project in this file which is impossible because you can’t import CS5 content into project file using AE CS3 . and at the end it gave this strange situation error. after clicking OK After Effects just freeze.